Malcolm Spence was born in Mississauga, Ontario, Canada and played youth hockey at the AAA level for the Mississauga Senators. During the 2021-2022 season he recorded 29 goals and 27 assists in 28 games. Following the season he was named the Greater Toronto Hockey League Player of the Year.
Spence was drafted second overall by the Erie Otters in the 2022 OHL Priority Selection Draft, after fellow 2025 NHL Draft prospect Michael Misa. During his rookie season in 2022-2023, the left winger recorded 16 goals and 26 assists in 64 games. He improved during his second season in Erie, scoring 19 goals and 43 assists in 66 games and was selected to compete in the 2024 CHL/USA Prospects Challenge.
Spence played well in International play over his young career and in 2023 he represented Canada at the Hlinka Gretzky Cup, recording four goals and three assists in five games to help win a gold medal. He was selected to represent Canada at the 2024 IIHF World U18 Championships and served as alternate captain, totaling three goals and four assists in seven games to win another gold medal.